Will the climate response to volcanic eruptions change in the future?

In the future, in a warmer world due to anthropogenic greenhouse gas forcing, the impact of natural forcing on climate could change dramatically.  However, it is not yet clear how strong a volcanic forcing as in the early 19th century will affect future climate. Previous studies show both an amplification of the surface cooling response, mainly due to an increase in upper ocean stability, and a weakening of the volcanic-induced surface cooling in a future climate state due to a reduced effective volcanic aerosol radiative forcing.

To assess how different climate states affect the climate response to volcanic forcing, we have performed MPI-ESM ensemble experiments under historical, 4xCO2 and present-day conditions with volcanic forcing equivalent to that of the early 19th century.  On these simulations, we have also tested explicable artificial intelligence methods to see if they are able to achieve a similar skill for specific fingerprints in the temperature record when the boundary conditions are very different from the present, as in the case of a 4xCO2 scenario.

We find that different changes in Arctic sea ice cover and northern hemisphere winter sea level pressure are induced by the same volcanic forcing under distinct climate states, while the large-scale average temperature response shows no significant differences.  The volcanic fingerprint in the surface temperature pattern is similar for all climate states for large volcanic eruptions in the first post-volcanic year, while the background state becomes relevant afterwards, as well as for smaller eruptions